A certain number of proposals such as those in documents EP 0878332, EP 1630026, WO 2006/032669, US 2007/0257570, WO 2007/083209 or WO 2009/124892 are known in this field.
In the present application, the expression “motorized hub” is used to denote the mechanical assembly comprising the hub, the hub carrier, the guidance of the hub with respect to the hub carrier, the electric drive and the hub braking means. The motorized hub is therefore intended on the one hand to accept a wheel fitted for example with a pneumatic tyre and, on the other hand, to support a vehicle, generally via suspension means. In the present application, the expression “motorized wheel” is likewise used to denote the mechanical assembly comprising the motorized hub defined hereinabove plus the corresponding wheel.
Document WO 2009/124892 describes such motorized hubs the design of which exhibits good compatibility with the solutions already adopted and validated by motor manufacturers for certain elements such as the suspension systems and the wheels. For this purpose, it is proposed that the shaft of the electric unit be positioned radially on the outside of the brake disc, the brake disc being positioned on the inboard side of the vehicle with respect to the hub carrier. According to a first alternative form depicted in FIGS. 1 and 2 of document WO 2009/124892, the hub rotates in a bore of the casing. The casing therefore acts as a hub carrier and also supports the brake caliper. The guidance rigidity of such a design proves to be insufficient. According to another alternative form depicted in FIG. 3 of that same document WO 2009/124892, the hub rotates about a stub axle, the said stub axle crossing the plane of the brake disc. The rigidity of this guidance also proves to be insufficient because of the great length of the stub axle. According to yet other alternative forms depicted in FIGS. 4 to 8 of that same document, the hub rotates in a bore of the casing but the brake caliper is this time held by the suspension arm rather than by the casing. These latter alternative forms, although satisfactory from a guidance standpoint, are very complicated to assemble and are therefore very expensive both from a manufacturing and from a maintenance standpoint.